The present invention relates to a single-use cartridge containing an ingredient intended to interact with an amount of water injected in the cartridge for preparing a liquid. The cartridge is typically used for preparing liquid food such as a nutritional liquid preparation, e.g., an infant formula, a soup or a beverage. The cartridge is typically inserted in a dispensing machine adapted for receiving the cartridge, for injecting water at a suitable temperature and therefore preparing quickly, hygienically and conveniently a liquid food from said cartridge.
A cartridge for preparing liquid food in a dispensing machine, such as an in-home delivery system, is known for example in WO 03/059778. The cartridge comprises a cup forming a chamber for holding the food ingredient, a puncturable delivery wall such as a flexible membrane forming a physical barrier that retains the ingredient in the chamber, a puncturing system for puncturing the wall by effect of water filling the chamber under pressure. The cartridge further comprises a collecting area to collect the liquid which passes through the punctured membrane and at least one outlet for delivering the liquid from the collecting area.
For certain ingredients, it is important to allow a sufficient interaction between water and the ingredients in the cartridge, e.g., mixing, brewing or dilution, and to avoid water preferred flow path that could traverse the substance and leave dry portions of ingredients, e.g. food powder, which are not wetted by water. A delayed opening of the delivery wall of the ingredient's chamber of the cartridge ensures that the largest amount of ingredient is wetted before the liquid can leave the cartridge. This delayed opening provides a way to reduce the preferred flow shortcut through the substance. It also ensures a full dissolution of the substance when this one is soluble. Indeed, for certain ingredients, it is necessary to obtain a complete dissolution of the substance in the chamber before the liquid can be released. It means that opening must occur when the chamber is entirely filled and mixed with the ingredient and a liquid mixture is obtained. If the membrane opens too early, dry ingredient such as solid lumps may be left in the chamber. This may result in a volume of delivery food liquid that does not reach the required concentration. For certain liquid preparations such as infant formula or other nutritional preparations, a low concentration of the delivered liquid is not acceptable, in particular for persons for which the intake of food and nutrients must be accurately controlled.
Another problem met with existing cartridges is that the flow of the food liquid must be delivered in a controlled manner. In particular, the flow of liquid must not be blocked, reduced or restricted in some way. This is important for providing a rapid, consistent and hygienic delivery in particular with sensitive food such as infant formulas.
Also, for certain liquid preparations, a significant amount of foam on the delivered liquid may be not desired because it could provide a too high solid concentration of the final liquid and/or a texture which is not appropriate for its intended use.
Therefore, the flow of liquid must be delivered in a controlled manner, preferably without risk of blocking, without splashing, therefore, preferably smoothly through the delivery outlet, while still an effective mixing or homogenization can take place in the chamber of the cartridge. This may be contradictory with the need for a certain opening delay in the cartridge to obtain sufficient interaction between water and the substance in the cartridge. Indeed, a delayed opening requires creating a rise of pressure in the chamber till the chamber is opened. When the chamber opens, e.g., the delivery membrane ruptures, the liquid tends to flow as powerful jets through the created openings. In particular, the membrane tends to collapse forming restriction areas which are prone to form high velocity jets in many possible uncontrolled directions.
Therefore, existing cartridges are not properly designed to provide both a delayed opening allowing a proper interaction between water and the substance, e.g., a proper dissolution or brewing of the ingredient in the cartridge, and a slow and directionally controlled delivery flow that enables a hygienic delivery, such as a direct delivery in the receiving receptacle, i.e., a baby bottle, a cup or glass, with a reduced risk of contamination outside of the receptacle.
WO2005/016094 relates to a coffee or tea pod comprising a spiked pod into which is positioned a lower filter layer and a foiled envelope. The water pressure forces both the lower filter layer and the foiled envelope against the spikes of the spiked pod. The punctures caused by the spikes allow the brewed beverage to pass therethrough while substantially maintaining the brewing material therein. The beverage leaves the pod through a plurality of holes distributed in the bottom of the pod.
EP1555218B1 relates to a cartridge for coffee or a soluble substance comprising a container, a lid and a filter designed to be positioned inside the container and above the bottom wall through which the beverage leaves. The bottom wall has a breakable portion designed to break when the liquid inside the cartridge reaches a pre-set pressure so as to form an aperture to allow beverage to be extracted from the cartridge. The breakable portion is obtained by means of grooves formed in a weakened portion of the bottom wall. One problem is that it is relatively difficult to control the resistance of the weakened portion that opens under the sole effect of the pressure of fluid in the cartridge to ensure a reproducible delay of the opening time from cartridge to cartridge. Thus, inconsistent opening times will cause beverages having different solids concentration and thus different quality.
EP1580143B1 relates to a cartridge for extracting a beverage from particulate substance contained therein by means of water under pressure, the cartridge comprising a cup portion with a cup port and a lid for closing the cup portion; the base of the cup portion comprising a plurality of ridges directly formed thereon and protruding towards the internal volume of the cartridge and a filter placed on the ridges to define a fine canalization between the filtering means and the cup port. The delayed opening is obtained by means of a slit or orifice valve that opens under an internal pre-set pressure. The filter must be sufficiently thick and rigid enough to resist the pressure and avoid its collapsing in the canalization. A disadvantage is the use of thick plastic material to resist the pressure and the high number of pieces necessary to form the cartridge which makes the cartridge complex and costly to manufacture.
WO2007/039032 relates to a cartridge of the same principle as the one of EP1580143B1 but with a safety cap which is mounted on the external surface of the cup port and partially closes the external open end thereof.